Composition and method



Patented Oct. 13, 1953 Charles W. Todd, Wilmington, Del., assignor to E. I. du Pont de Ncmnonrs & Company, Wilmington, Del, a corporation oi Delaware No Drawing. Application February 14, 1952, Serial N- 271,63

9 Claims. (CL ll-2.6)

This invention relates to herbicidal compositions and methods employing as an essential active ingredient a dior tri-substituted urea of the kind more particularly described below.

This application is a continuation-in-part-of my copending applications: Serial No. 131.498 filed December 6, 1949, Serial No. 186,118 filed September 21, 1950, Serial No. 231,061 flled June '11, 1951, Serial No. 231,062 flied June 11, 1951, and Serial No. 228,992 filed May 29, 1951, all of which are now abandoned except application Serial No., 186,118.

Because of the enormous losses caused by weeds, the problem of weed control is a major one in agricultural economy. Although 2,4-dichlorophenoxyacetic acid (2,4-D). 'trichloroacetic acid and related synthetic chemicals have proven effective for the eradication of a number of objectionable leafy plants, these chemicals have not been particularly successful in the control of obnoxious grasses such as Johnson grass, Bermuda grass, nut grass, quack grass and the like. There is a great need,.therefore, for additional herbicides for the control of weeds resistant to the presently available products.

It is an object of this invention to provide new herbicidal compositions and methods. A further object is to provide new herbicidal compositions effective for the control of weeds and obnoxious grasses. Other objects will appear hereinafter.

The foregoing and other objects of the invention are attained by means of herbicidal compositions .containing as an essential active ingredient a 1,3-substituted urea selected from compounds represented by the formulae:

Y RI! Y- an @Nao ON/ x. \R

In the above formulas; R is an alkyl radical containing up to two carbon atoms, i. e., methyl or ethyl; R" is selected from hydrogen and alkyl up to two carbon atoms; X is halogen; Y is selected from hydrogen, R and OR, where R is a monovalent aliphatic hydrocarbon radical of up to four carbon atoms having at most one unsaturation and that ethylenic; Z is selected from alkenyl and alkenoxy radicals, the alkenyl radical in said alkenyl and alkenoxy substituents containing up to four carbon atoms; and n is a positive integer up to two. The compounds are still further characterized by having the arcmatic substituent (i. e., the substituent containing the benzene nucleus) have hydrogen on at least one of the nuclear carbons ortho to the nuclear carbon to which the urea nitrogen atom is linked. In other words, at least one of the ortho positions is unsubstituted.

In the above formulas, X is preferably chlorine, R is preferably methyl, and Y is preferably hydrogen or methyl.

The Lit-substituted ureas employed in the herbicidal compositions and methods of this invention can be prepared by conventional methods, for example. by reaction of a primary or secondary amine with an isocyanate, isothiocyanate, carbamyl chloride, or thiocarbamyl chloride. More specifically, the following equations illustrate various methods which can be suitably employed for the preparation of representative ureas.

@NHi-Hcmm-o 001. i

o N-g-N-cm (cumin-no] A Jan.

The above reactions are accomplished by bringing the amine in contact with one of the other reactants specified, usually in chemically equivalent amounts, and, if necessary. heating I Equation 9, it is advantageous to use an acid acceptor, for example, a tertiary amine such as triethylamine, dimethylaniline, pyridine, and the like. Ordinarily, temperatures in the range of to 100 C., but preferably 15 to 75 C., are satis factorily employed for the above reactions.

Illustrative of the 1,3-substituted ureas employed in the herbicidal compositions and methods of the invention are:

3- (p-chlorophenyl) -1-methylurea 3-(m-chlorophenyl) -1-methylurea 3- (o-chlorophenyl) -1 -methylurea 3- (p-bromophenyl) -1-methylurea 3-(p-iodopheny1) -1-methylurea 3- (m-fiuorophenyl) -1-methylurea 3- (p-chlorophenyl) -l-ethylurea 3- (3-chloro-p-tolyl) -1-1nethylurea 3- (2-chloro-p-tolyl) -1-methylurea 3-(3-chloro-4-methoxyphenyll -1-methylurea 3- (3-ch1oro-4-allyloxyphenyl) -1-methylurea 3- (3-chloro-4-isopropoxyphenyl) -1-methylurea 3- (3-chloro -4-ethylphenyl) -1-methylurea 3- 3-chloro -4-sec.butylphenyl) -1-methy1urea 3-(3-chloro-4-isopropylphenyl) -1-methylurea 3-(2-methyl-4-chlorophenyl) -1-methylurea 3-(3,4-dichlorophenyl) -1-methylurea 3- (3,4-dichlorophenyl) -1-ethylurea 3-phenyl-1-methylurea 3- (p-tolyl) -1-methylurea 3- (3,5-dich1oro-p-tolyl) -1-methylurea 3- (4-see.butylphenyl) -1 -methylurea 3- (4-allyloxyphenyl) -1-methylurea 3- (4-isopropylphenyl) -1-methylurea 3- (3,4-dimethylphenyl) -l-methylurea FGIZ-dimethylphenyl) l,1-dimethylurea 3-(2,4-dimethylphenyl) 1,1-dimethylurea 3- (2,5-dimethylphenyl) l-methylurea 3- (2,5-dimethylphenyl) -1,1 -dimethylurea 3- (p-methoxyphenyl) -1-methylurea B-phenyl-l-ethylurea 3- (p-tolyl) -1-ethylurea 3-phenyl-1,1-dimethylurea EiTp-tolyl) -1,1-dimethylurea 35m -1,1-dimethylurea Ti-To-tolyl) -1,1-dimethylurea 3- (4-yinylphenyl) -l,1-dimethylurea 3- (4-ethylphenyl) -l,ldimethylurea S-phenyl-l-methyl-l-ethylurea B-(p-tolyl) -1-methyl-1-ethylurea 3-phenyl-1,l-diethylurea B-(p-tolyl) -1,1-diethylurea 3- (4-methoxypheny1) -l,1-dimethylurea 3- (4-ethoxyphenyl) -1,l-dimethylurea 3- (4-ethylphenyl) -l-rnethylurea 3- (4-allyloxypheny1) -l,l-dimethylurea 3- (-isopropoxyphenyl) l ,l-dimethylurea 3- (4-isobutoxyphenyl) -1,1-dimethylurea 3- (4-isopropylphenyl) -1,1-dimethylurea 3- (4-tert.butylphenyl) -1,1-dimethylurea 3- (2,4dichlorophenyl) -1,1-dimethylurea 3-(2,5-dichlorophenyl) -l,l-dimethylurea 3-(2,3-dichlorophenyl) -l,l-dimethylurea 3- (2,5-dichlor ophenyl -l-methyl-l-ethylurea 3- (2,5-dlchlorophenyl) l,l-diethylurea 3= (p-chlorophenyl) -l,l-dimethylthiourea 3 (or -chiorophenyl) 1,1-dimethylthiourea 3= 12=cldoraphenyl ii methybl-ethylthiourea S-(p-chlorophenyl) -1,1-diethylthiourea 3- p-bromophenyl) 1,1-dimethylthiourea 3- (p-iodophenyl) -l,l-dimethylthiourea 3- (m-fluorophenyl) 1,1 -dimethylthiourea 3- (3-ch1oro-p-tolyl) -1,1-dimethy1thiourea 3- (3,5-dichloro-p-tolyl) -1,1-dimethylthiourea 3-(3-chloro 4 methoxyphenyl) -l,1-dimethylthiourea 3-(3 chloro 4 allyloxyphenyl) -1,l-dlmethylthiourea 3- (3-chloro-4-ethylphenyl) -1,1-dimethylthiourea 3-(3-chloro 4-- secloutylphenyl)-l,l-dimethylthiourea 3-(3-chloro 4 isobutoxyphenyl) -1,1-dimethylthiourea 3- 3,4-dichloropheny1) -1-methyl-1-ethylthiourea 3- (2,5-dichlorophenyl) -1,1-dimethylthiourea 3-(p-chlorophenyl) -1-methylthiourea 3-(m-chlorophenyl) -1-methylthiourea 3-(3-chloro-p-tolyl) -1-methylthiourea 3-(3,4-dichlorophenyl) -1-methylthiourea 3-(4-isobutylphenyl) -1,1-dimethylthlourea 3-phenyl-1-methy1thiourea 3-(p-tolyl) -1-methylthiourea 3-phenyl-1,1-dimethylthiourea 3-phenyl-1,1-diethylthiourea 3- (p-tolyl) -1,1-dimethy1thiourea 3- (4-methoxyphenyl) -1,1-dimethylthiourea 3- (4-allyloxyphenyl) -1,1-dimethylthlourea 3- (4-sec.butylphenyl) -1,1-dlmethylthiourea 3-(4-ethylphenyl) -1,1-dimethylthiourea 3-(4-isopropylphenyl) -1,1-dimet hylthiourea 3- (4-tert.butylphenyl) -1,1-dimethylurea 3-(3-chloro-4-tert.butylphenyl) -1-methylurea 3- (3-chloro-4-vinyloxyphenyl) -1.1-dimethylurea 3- (3-chloro-4-allyloxyphenyl) -1,1-dimethylurea 3- (3-ch1oro-4-allyloxyphenyl) -1-methylurea 3 3,5-dichloro-4-allyloxyphenyl) -1,1-dimethylurea 3-(3,5-dichloro-4-allyloxyphenyl) -1-methylurea 3-[3-chloro 4 (2 butenoxy)phenyll-1,1-dimethylurea 3- [4- (2-butenoxy) phenyl] -1,1-dimethylurea 3-[3-chloro 4 (2-butenoxy)phenyl] -1-methylurea 3- (3-chloro-4-vinylphenyl) -1,1-dimethylurea 3- 3-chloro-4-vinylphenyl) -1-methylurea The herbicidal compositions of the invention are prepared by admixing one or more of the 1,3- substltuted ureas defined heretofore, in herbicidally efiective amounts, with a conditioning agent of the kind used and referred to in the art as a pest control adjuvant or modifier in order to provide formulations adapted for ready and eflicient application to soil or weeds (1 e., unwanted plants) using conventional applicator equipment.

Thus the herbicidal compositions, or formulations, are prepared in the form of either powdered solids or liquids. The liquid compositions, whether solutions or dispersions of the active substituted urea in a liquid diluent, contain as a conditioning agent a surface-active dispersing agent in amounts sufilcient to render the liquid composition readily dispersible in water for application as an aqueous spray. The powdered solid herbicidal compositions preferably also contain a surface-active dispersing agent in amount suflicient to impart water dispersibility to the powdered compositions, altho the surface-active dispersing agent can be omitted if it is desired to apply the compositions by dusting rather than spraying. However, even tho the surface-active dispersing agent be omitted in the latter event, the herbicidal composition will still contain, of

course, a powdered solid carrier or diluent as a conditioning agent.

The surface-active dispersing agents employed in the herbicidal compositions of the invention are sometimes referred to in the art as wetting, dispersing, or penetrating agents. They are agents which cause the compositions, whether in liquid or powdered solid form, to be easily dispersed in water to give aqueous sprays, They can be of the anionic, cationic, or nonionic type and include, for example, sodium and potassium oleates, the amine salts of oleic acid such as morpholine and dimethylamine oleates, the sulionated animal and vegetable oils such as sulionated fish and castor oils, sulionated petroleum oils, sulfonated acyclic hydrocarbons, sodium salt of lignin sultonic acid (goulac), alkylnaphthalene sodium sulfonate, sodium salts of suli'onated condensation products of naphthalene and formaldehyde, sodium lauryl sulfate, disodi m monolauryl phosphate, sorbitol laurate, pentaerythritol monostearate, glycerol monostearate, diglycol oleate, polyethylene oxides, ethylene oxide condensation products with stearyl alcohol and octylphenol, polyvinyl alcohols, salts, such as the acetate of polyamines from reductive amination of'ethylene/carbon monoxide polymers, laurylamine hydrochloride, laurylpyridinium bromide, stearyltrimethylammonium bromide, cetyldimethylbenzyl ammonium chloride, lauryldimethylamine oxide, and the like. Generally, the surface-active agent will not comprise more than about to by weight of the composition, and in certain compositions the percentage will be 1% or less. Usually the minimum lower concentration will be 0.1

Powdered or dust compositions of the invention whether or not also modified with a surfaceactive dispersing agent to make them water dispersible are prepared by admixing one or more of the active substituted ureas with finely divided solids, preferably, talcs, natural clays, pyrophyllite, diatomaceous earth, and flours such as walnut shell, wheat, redwood, soya bean, and cottonseed flours. Other inert solid carriers which can be used to prepare the herbicidal formulations include magnesium and calcium carbonates, calcium phosphate, sulfur, lime, etc. either in powder or granular form. The percentage by weight of the essential active ingredients will vary according to the manner in which the composition is to be applied but, in general, will be 0.5 to 95% by weight of the herbicidal composition.

similar vehicles such as cottonseed oil, olive oil, lard, paraflin oil, hydrogenated vegetable oils, etc. Adhesives such as gelatin, blood albumin, resins, for example, rosin, alkyd resins and the like, can also be used in certain compositions to increase retention or tenacity of deposits following application.

The herbicidal compositions are applied either" as a spray or a dust to the locus or area to be protected from undesirable plant growth, commonly called weeds, 1. e., plants growing where they are not wanted. Such application can be lake bottoms, it will be convenient to use a pellet form of the composition.

In another method or application for weed con trol, the ureas are incorporated with fertilizers to form either powdery or granular herbicidal compositions that can be used in the cultivation of agricultural crops.

The active ingredients are, of course, applied in amount suflicient to exert the desired herbi- ,cidal action. The amount or herbicidally active compounds present in the compositions as actu ally applied for destroying or preventing weeds will vary with the herbicidal activity of the active ingredients, the purpose for which the application is being made (i. e., whether for short term or long term control), the manner of application, the particular weeds for which control is sought, and like variables. Certain of the specific examples to follow will illustrate various kinds and amounts or application and the results obtained thereby. In general, the herbicidal compositions as applied in the form of a spray or a dust will contain from about 0.02% to 95% by weight of herbicidally active ingredient.

The solid and liquid compositions described and employed herein for application of the essential active herbicidal ingredient all have the common property of permitting application of the herbicidal compositions through suitable The active substituted ureas can be dissolved in organic solvents such as cyclohexanol, turiural, acetone, isobutanol, ethanol, isopropylacetate, and the like in the preparation of liquid compositions of the invention. Concentrated water-dispersible liquid compositions can be prepared by incorporating the ureas and surfaceactive dispersing agents in various organic liquids such as furiural, methanol, isopropanol, isobutanol, xylol, cresol, cyclohexanone, acetone, methyl ethyl ketone, kerosene, trichloroethylene, dimethylformamide, dimethylacetamide, alkylated naphthalenes, and the like. Such compositions are readily dispersible in water and provide excellent aqueous herbicidal sprays for fleld application. The proportion of surface-active dispersing agent to urea can be 0.1 to 100% by weight in the water-dispersible herbicidal compositions.

The herbicidal compositions of the invention can also have incorporated therein oils, fats or jets, nozzles, or spreaders adapted" to the handling of granular materials onto the plants being treated and will, for convenience, be designated as fluent carriers. The fluent carriers with which this invention is primarily concerned are non-solvent fluent carriers.

In order that the invention may be better understood, the following examples are given in addition to the examples already given above. The examples illustrate typical hebicidal compositions of the invention, methods for their preparation, herbicidal applications, and the results obtained. The numbers following the tabulated ingredients represent parts by weight 01' the ingredients in the respective compositions.

EXAMPLE 1 Water-dispersible powders The following powdered compositions are adapted for dispersing in water for application as a spray for the destruction and prevention of weeds. The powdered compositions are made by intimately mixing the listed ingredients using conventional mixing or blending equipment and then grinding the mixture to give a powder havan average particle size less than about 5( microns.

3-(3-chloro-p-tolyl)-l-methylurea 75 Fullers earth 23315 Sodium lauryl sulfate, 50% (wetting agent) Methyl cellulose, 15 cps. (dispersing agent) .25:

as as) (2,-dichlorophenyl) -l,l-dimethgiur Sodium disulfonate of dibutvl phenyi (wetting and dispersing agentll. I Bentonite EXAMPLE 2 Dust formulations The following compositions are adapted for direct application as dusts for the destruction or prevention of weeds using conventional dusting equipment. The dusts are made by blending or mixing the ingredients and grinding the m": to give compositions having an average par ticle size less than about 50 microns,

3-(m-tolyl)-l,l-dlmethylurea 2o Talc -e as E 3-(2,4-dichlorophenyl) -l,l-diethylurea ......r 5 Cottonseed oil 4 Walnut shell flour 9i Gi li-water dispersihie The following powdered compositions are The powders are made by and as in the case of the powders 2,

li-phenyhl,l-diethylurea Kl Allrylated ar d polyether alcohol (wetting and dispersing agentlmw, earth 263 3 (3,5-dichloro-p-tolyl)-l-metliyluiea Et' dem oxide stearatedaurate (emulsiiii ing agent) Pyrophyllite ,.e .i it

Water-dtspersihlc Eiq'aid compositions The following compositions in a liquid form and are adapted for addition water to give aqueous dispersions for application as sprays. The urea herbicides are generally quite insoiuhle most oils. Therefore, the liquid som positions are not complete Gil tained with herbicidal compositions or t v for each. plant species was the concentrati I but rather are dispersions of solid in an oil. The liquid or fluid compositions shown are prepared by thoroughly mixing and dispersing the active compounds and conditioning agent or agents in an organic liquid diluent 3-(3,4-dlchlorophenyl)-l-methylurea 25 Long chain fatty alcohol sulfate (emulsiiy ing agent) 2 Goulac (dispersing agent) s Kerosene 3-phenyl-lJ-dimethylthlourea Alkvlatcd aryl polyether alcohol (wetting and emulsifying agentl 3 Methyl cellulose v(dispersingagent) l Kerosene 66 10c EXAMPLE 5 Granular compositions The following compositions are adapted for application by means of a fertilizer spreader apparatus or similar equipment. The compositions are readily prepared by mixing the ingredients with water to form a paste The paste is then extruded, dried, and ground to give the desired granular size. Preferably, the granules will be in the order of one-thirty second to one quarter inch diameter, I

3-(p-chlorophenyl)-i,l-dimethylthiourea and 3-(p-tolyl.) -l,i-dimethylurea each formulated in the foregoing example killed the quack in 12 weeks when sprayed on the to the rumor? point from aqueous dis scion com taining 3% by weight oi test s Following is a tabulation of tiori containing various of the active (305 pounds. In. each case, the formulation employe o 80% by weight of the active compound, 18% by weight of powdered solid diluent, and 2% weight oi wetting and dispersing agents.

Formulations of each of the compounds were dispersed in water to give aqueous sprag, compo sitions containing various concentrations of each oil the active ingredients. Each aqueous dispersion was sprayed on three-month. old quack grass plants from root cuttings and on sixweek old Johnson grass seedlings to the rust-o point.

, 9 the herbicidaliy active compound in the aqueous dispersion sprayed on the plants which was suiflcient to effect kill of the Johnson grass seedlings in five weeks and the kill oi the quack grass in three months.

Johnson Ex- Quack ample Compound m an Percent Percent 7 3-phenyl-Ll-dimethyiurea; 3 3 8- 3-(p-cb orophenFDd-methylurea' 3 3 9. 3-(p-tolyl)-1,l-d methylurea 3 3 10 a-(p-sec. butylphen l)-i,l-dimethylurea.. 3 3 1i 3-(p-allyloxypbenyl -l,l-dimethylurea... 3 3 l2 3-?,tdichlorophenyl)4-methylurea.. 1 3 13 3- p-bromophcnyl) l,l-dimethylthiourea 3 3 where R is alkyl up to two carbon atoms; R" is selected fromthe group consisting of hydrogen and alkyl up to two carbon atoms; X is halogen; Y is selected from the group consisting of hydrogen, R and OR, where R is a monovalent aliphatic hydrocarbon radical otup to four carbon atoms having at most one unsaturation and that ethylenic; Z is selected from the group consisting oi? alkenyl and alkenoxy radicals, the alkenyl radical in said alkenyl and alkenoxy substituents containing up to four carbon atoms; and n is a positive integer up to two, the aromatic substituent having hydrogen on at least one of the nuclear carbons ortho to the nuclear carbon to which the urea nitrogen atom is linked.

l0 2. A herbicidal composition comprising a conditioning agent and, in amount suflicient to exert herbicidal action, a Lil-substituted urea selected from the group consisting of compounds represented by the formulas:

and

where R is alkyl up to two carbon atoms; R" is selected from the group consisting of hydrogen and alkyl up to two carbon atoms; X is halogen; Y is selected from the group consisting of hydrogen, R and OR, where R is a monov-alent aliphatic hydrocarbon radical oi up to tour carbon atoms having at most one unsaturation and that ethylenic; Z is selected from the group consisting of alkenyl and alkenoxy radicals, the alkenyl radical in said alkenyl and alkenoxy substituents containing up to four carbon atoms; and n is a positive integer up to two, the aromatic substituent having hydrogen on at leastone of the nuclear carbons ortho to the nuclear carbonto which the urea nitrogen atom is linked.

3. A herbicidal composition according to claim 2 containing a non-solvent fluent carrier as a conditioning agent.

4. A herbicidal composition according to claim 2 containing a surface-active dispersing agent as a conditioning agent.

5. A herbicidal composition comprising 3-(pchlorophenyl) -1-methylurea in amount suflicient to exert herbicidal action and a surface-active dispersing agent in amount sufllcient to impart water dispersibility to the composition.

6. A herbicidal composition comprising 343,4- dichlorophenyi) -1-methylurea in amount sufficient to exert herbicidal action and a surfaceactive dispersing agent in amount sufficient to impart water dispersibility to the-composition.

7. A herbicidal composition comprising 3- phenyl-1,1-dimethylurea in amount suflicient to exert herbicidal action and a surface-active dispersing agent in amount suflicient to impart water dispersibility to the composition.

8. A herbicidal composition comprising 3-(pto1yl)-1,1-dimethylurea inamount sumcient to exert herbicidal action and a surface-active dispersing agent in amount suflicient to impart water dispersibility to the composition.

11 9. A herbicidal composition comprising 3-(mtolyl) -1,1-dimethylurea in amount sufficiem; to exert herbicidal action and a. surface-active disparsing agent .in amount sufl'icient to impart watez" disperslbility to the composition.

, CHARLES W. TODD.

References Cited. in the fiie of this patent,

UNITED STATES PA'I'EN'IPS Dot o mm mmm m .w 15,

Number Number H2 Name Date Jones Dec. 19, 194% Sexton June 7, 19%! FOREIGN PATENTS Country Dam Great Britain Jan. 30, 1946 Thompson et aL, Botanical Gazette," voi. MD? 946) pages 

2. A HERBICIDAL COMPOSITION COMPRISING A CONDITIONING AGENT AND, IN AMOUNT SUFFICIENT TO EXERT HERBICIDAL ACTION, A 1,3-SUBSTITUTED UREA SELECTED FROM THE GROUP CONSISTING OF COMPOUNDS REPRESENTED BY THE FORMULAS: 